Various III-V compounds are being investigated for use in high-power electronics applications. These compounds include III-V nitrides such as gallium nitride (GaN), aluminum gallium nitride (AlGaN), and aluminum indium gallium nitride (AlInGaN). These compounds can be used to form High Electron Mobility Transistors (HEMTs) for use in high-power high-voltage applications.
Many conventional GaN-based transistor devices operate in a normally-on state or in a depletion mode. This typically requires the use of a negative bias voltage in order to turn off the transistor devices. The use of negative bias voltages is often undesirable. While some normally-off GaN-based transistor devices have been proposed, those devices also suffer from various disadvantages.